Constraints on primordial non-Gaussianity from the cross-correlation of DESI luminous red galaxies and Planck CMB lensing

¹ Instituto de Astrofísica de Canarias, C/ Vía Láctea, s/n, E-38205 La Laguna, Tenerife, Spain
² Department of Physics & Astronomy, University of Rochester, 206 Bausch and Lomb Hall, P.O. Box 270171 Rochester, NY 14627-0171, USA
³ Departamento de Astroísica, Universidad de La Laguna, Avenida Francisco Sánchez, s/n, E-38205 La Laguna, Tenerife, Spain
⁴ Department of Physics and Astronomy, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada
⁵ Perimeter Institute for Theoretical Physics, 31 Caroline St. North, Waterloo, ON N2L 2Y5, Canada
⁶ Waterloo Centre for Astrophysics, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada
⁷ Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
⁸ Department of Physics, Kansas State University, 116 Cardwell Hall, Manhattan, KS 66506, USA
⁹ Physics Dept., Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
¹⁰ Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano, Via Celoria 16, I-20133 Milano, Italy
¹¹ Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, UK
¹² IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
¹³ Instituto de Física, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica, Ciudad Universitaria, Cd. de México C. P. 04510, México
¹⁴ NSF NOIRLab, 950 N. Cherry Ave., Tucson, AZ 85719, USA
¹⁵ University of California, Berkeley, 110 Sproul Hall #5800, Berkeley, CA 94720, USA
¹⁶ Departamento de Física, Universidad de los Andes, Cra. 1 No. 18A-10, Edificio Ip, CP 111711 Bogotá, Colombia
¹⁷ Observatorio Astronómico, Universidad de los Andes, Cra. 1 No. 18A-10, Edificio H, CP 111711 Bogotá, Colombia
¹⁸ Institut d’Estudis Espacials de Catalunya (IEEC), c/ Esteve Terradas 1, Edifici RDIT, Campus PMT-UPC, 08860 Castelldefels, Spain
¹⁹ Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth PO1 3FX, UK
²⁰ Institute of Space Sciences, ICE-CSIC, Campus UAB, Carrer de Can Magrans s/n, 08913 Bellaterra, Barcelona, Spain
²¹ Fermi National Accelerator Laboratory, PO Box 500 Batavia, IL 60510, USA
²² Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
²³ Center for Cosmology and AstroParticle Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, OH 43210, USA
²⁴ Department of Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, OH 43210, USA
²⁵ The Ohio State University, Columbus, 43210 OH, USA
²⁶ School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
²⁷ Department of Physics, Southern Methodist University, 3215 Daniel Avenue, Dallas, TX 75275, USA
²⁸ Department of Physics and Astronomy, University of California, Irvine 92697, USA
²⁹ Sorbonne Université, CNRS/IN2P3, Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), FR-75005 Paris, France
³⁰ Departament de Física, Serra Húnter, Universitat Autònoma de Barcelona, 08193 Bellaterra, (Barcelona), Spain
³¹ Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Edifici Cn, Campus UAB, 08193 Bellaterra, (Barcelona), Spain
³² Institució Catalana de Recerca i Estudis Avançats, Passeig de Lluís Companys, 23, 08010 Barcelona, Spain
³³ Department of Physics and Astronomy, Siena College, 515 Loudon Road, Loudonville, NY 12211, USA
³⁴ Department of Physics & Astronomy and Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT PACC), University of Pittsburgh, 3941 O’Hara Street, Pittsburgh, PA 15260, USA
³⁵ Departamento de Física, DCI-Campus León, Universidad de Guanajuato, Loma del Bosque 103, León, Guanajuato C. P. 37150, Mexico
³⁶ Instituto Avanzado de Cosmología A. C., San Marcos 11 – Atenas 202. Magdalena Contreras, Ciudad de México C. P. 10720, Mexico
³⁷ Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía, s/n, E-18008 Granada, Spain
³⁸ Departament de Física, EEBE, Universitat Politècnica de Catalunya, c/Eduard Maristany 10, 08930 Barcelona, Spain
³⁹ Physics Department, Yale University, P.O. Box 208120 New Haven, CT 06511, USA
⁴⁰ Department of Astronomy, The Ohio State University, 4055 McPherson Laboratory, 140 W 18th Avenue, Columbus, OH 43210, USA
⁴¹ Department of Physics and Astronomy, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, Republic of Korea
⁴² CIEMAT, Avenida Complutense 40, E-28040 Madrid, Spain
⁴³ University of Michigan, 500 S. State Street, Ann Arbor, MI 48109, USA
⁴⁴ Department of Physics, University of California, Berkeley, 366 LeConte Hall MC 7300, Berkeley, CA 94720-7300, USA

^⋆ Corresponding author: jrbermejo@iac.es

Received: 14 December 2024
Accepted: 14 April 2025

Abstract

Aims. We use the angular cross-correlation between a luminous red galaxy (LRG) sample from the Dark Energy Spectroscopic Instrument (DESI) Legacy Survey data release DR9 and the Planck cosmic microwave background (CMB) lensing maps to constrain the local primordial non-Gaussianity parameter, f_NL, using the scale-dependent galaxy bias effect. The galaxy sample covers approximately 40% of the sky, contains galaxies up to redshift z ∼ 1.4, and is calibrated with the LRG spectra that have been observed for DESI Year 1 (Y1).

Methods. We apply a nonlinear imaging systematics treatment based on neural networks to remove observational effects that could potentially bias the f_NL measurement. Our measurement is performed without blinding, but the full analysis pipeline is tested with simulations including systematics.

Results. Using the two-point angular cross-correlation between LRG and CMB lensing only, we find f_NL = 39₋₃₈⁺⁴⁰ at the 68% confidence level, and our result is robust in terms of systematics and cosmological assumptions. If we combine this information with the autocorrelation of LRG, applying a scale cut to limit the impact of systematics, we find f_NL = 24₋₂₁⁺²⁰ at the 68% confidence level. Our results motivate the use of CMB lensing cross-correlations to measure f_NL with future datasets, given its stability in terms of observational systematics compared to the angular autocorrelation. Furthermore, performing accurate systematics mitigation is crucially important in order to achieve competitive constraints on f_NL from CMB lensing cross-correlation in combination with the tracers’ autocorrelation.